I have piece of text with a drop shadow on top of a box which has an inner shadow. In both cases, the shadows are CMYK black, with 100% opacity, applied using the Multiply method.

When designing, things appear correctly (note background is CMYK magenta, but will change once this issue is resolved):

When outputting in the Press format, with everything left as defaults, then two issues are seen, firstly is the Yucky Box Problem, the second is the drop shadow has lost it's colour, and looks as it does if I choose Normal for the shadow type. Note the PDF viewer is Apple Preview in Lion:

If I embed the CMYK colour profile I'm using (Coated FOGRA39), then the YBP goes away, but the colour of the shadow is still wrong:

Finally, if I force the transparency to be flattened, it appears correctly but with a thin white line (note profiles are not being embedded in this case):

Case 1

Case 2

Case 3

Case 4

What I would like to know is how to ensure the output is as it should be in the final case, but without the white line, i.e. without flattening. It's worth noting that if the text is located in the main, white, area of the page, then it works correctly in all cases (except the Yucky Box Problem situation which is easily resolved). Thanks in advance!

That seems to have resolved the problem. Interestingly, the 'Yucky Box Problem' doesnt seem to occur regardless of whether I'm importing the profile or not, I guess Adobe Reader is doing it's own stuff with the colour space which Preview isn't. Thanks again for your help!